The proposed project will examine two major aspects of the regulatory biochemical functions of glucocorticoids in specific noradrenergic and serotonergic neurons in the brain. One aspect is concerned with the biochemical role of these hormones in the regulation of tyrosine hydroxylase and tryptophan hydroxylase. The other aspect is concerned with the mechanisms of a direct hormonal action on nerve terminals in regulating the uptake of precursor amino acids, tyrosine and tryptophan. The project will also seek basic information: the development of cytosol glucocorticoid receptor, and the regulatory effect of glucocorticoids on adenyl cyclase activity, both to be examined specifically in the locus coeruleus and raphe nuclei. The overall aims of the project are (1) to clearly define the central monoamine neurons as target cells for glucocorticoids, and (2) to establish solid models of hormone function in these neurons: enzyme regulation and direct interaction with nerve terminals. Since glucocorticoids are intimately linked to environmental "stress" a better identification of the action of these hormones on the brain may contribute to the understanding of brain-environmental interaction and thereby stress-related mental illnesses.